Reversible counter



May 6, 1958 M.-;H.- HAYES ETAL REVERSIBLE COUNTER 3 Sheets-Sheet 1 Filed April 26, 1954 www.

May 6, 1958 M. H. HAYES ETAL 2,333,475

REVERSIBLE COUNTER Filed April 26, 1954 s she'ets-sheet 2 /Il ll'l llllll [All Em n M. H. HAYES Erm. .2,833,476

May 6, 1958 REVERSIBLE CQUNTER Filed April 26, 1954 3 Sheets-Sheet 5 y United States Patent@ In many digital computer, automatic control and instrumentation problems, devices are necessary to count large numbers of pulses at extremely rapid rates. Many of these counting or translating devices must add.v o'r sub' tract, i. e. be reversible. As an example, a reversible counter is vused in connection with output signals from an interferometer in Patent No. 2,604,004 to Elihu Root for the purpose of counting interference fringes. The counter used therein must be reversible in order to follow motion in two directions. VAs anotherv example, Patent No. 2,656,106 to H. P. Stabler shows -a reversible pulse counter used as a shaft quantizer or digitizen In order that Shaft rotation in bothdirections may be measured,fa,;,re'versible counter must ybe employed. Fui-,there` more, itis desirable that such counters be direct-coupled. As is well-known in the' electronic arts, direct-coupled circuits are less susceptible `to .noisej and more reliablel because capacitors, which frequentlyV fail andmust be replaced, are eliminated from the signal circuits.;

It is therefore an object oftheinvention to provide improved reversible direct-coupled counters. f

It is a further object of the inventionto provide im provedv reversible counting4 circuits which may be cascaded to, identical lhigher order counting circuits to provide counts of extremely large numbers.

-Itis vanother object of the invention to provide reversible, directfcoupled counters having no electrical backlash. v

Itis an additional object of the invention to provide improved reversible counters utilizing a high speed gasefl ous glow discharge counting tube.

It is another object of the invention to provide an im- `proved reversible counting circuitv operable to receive input voltages .phased according to direction.

It is yet a further object of lthe invention to providea new and improved counting circuit which may be readily utilized in constructing counters which will count according to anyldesired basenumber above foun Other objects of the invention will in part be obvious,

and will in part appear hereinafter.

The invention accordingly vcomprises the features of' construction, combinations of elements, and arrangements ceA tubes used in practising the invention during vten'unit counts or one complete counting cycle;

Fig. 4 is a diagram showing graphically the'potentials' appearing at certain output terminals connected to the l gaseous'glow transfer tubes during ten unit counts or onev complete countingcycle, and also showing the voltages? derived to actuate a succeeding, higher order countingl stage;y

Fig. 5 is an electrical schematic diagram showingV atypical lcountingy stage -constructed accordingto the in-4 vention;

Fig. 6 is an electrical schematic diagram lof`a bi-'stable' flip-Hop circuit which may be utilized in the invention;

Fig. 7 illustrates a -re-set switchingcircuit which may be utilized to reset the counting circuitsto a predeterfmined desired count;

Fig. 8 shows in block diagram formi (for sake of clarity) .how counting circuits constructed according to the invention may becascaded; Y Fig. 9a illustrates graphically various circuit potentials in an -alternative embodiment of our invention in which a diierent base number is utilized, and

Fig. 9b illustrates graphically various circuit potentials in yet another embodiment of the invention for counting.v

with another base number. In Figures 2, 3, 4, 9a and 9b,

the potentials plotted are not drawn to any particularv scale.v For convenience, all the pulses are shown as being of the same magnitude, and those yacquainted with the, electrical arts will recognize that the diagrams do not attempt to show relative pulse magnitudes, but merely high or low voltage states.

The present invention utilizes as its lbasic counting or4 translating element an Ericssonwvalve. GS-lOC, ,which is manufactured in England and distributed in the United States by Atomic Instruments, Inc. of Boston, Massachu,

' setts. The operation of this glow transfer tube itself is of parts, which will beexempliiied in the constructionsv hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a `better understanding of our inventiomreference may be had to the accompanying drawings, in'which:

Fig. 1 is` an electrical4 schematic diagram of the glow transfer tube utilized`as a basic counting element in a preferred embodiment of the invention; i n

Fig. 2 is a diagram showing graphically the potentials applied to certain elements of the device of Fig. 1 during one. unit count;

Fig. 3 is a diagram showing graphically the potentials appearing on certain elements of a pair of gaseous glow described and explained in detail in Electronic Engineer ing, vol. 22, No. 173 (1950) in an. article The Dekatronv by Bacon and Pollard, and therefore only a brief description of its yoperation will be set forth'herein.` It will become apparent, however, as the` description proceeds, that the present invention is not limited to precisely that particular glow transfer tube, and that similar tubes may be utilized in practising the invention. Fig. l showsschematically a cold cathode gaseous'discharge valve GT-l having a total of thirty-one elements. Ten of these elements are referred to for convenience ,asfcathodesf and are identified in'Fig. l by the symbols K-0 to' K-9,.

The ten cathodes are arranged equidistantly in circular.,

array about a disc-shaped anode P within a gas-filled envelope E, and terminals for external connectionsv are.'

brought out of the envelope.

Situated between each adjacent 'pairlof cathodes are two similar elements which may be referred to for convenience'as guides Those guides located immediately clockwise from their respective cathodes are kall intercom;y

nected and maybe referred to collectively as @guide set one, and an external terminal G1 is providedforconnection to guide set one. Those guides disposed imme-vk diately clockwise from the G-l guides are all interconnected and may be referred to collectively as guide setv two.

If a voltage in excess of the ionization potential is applied to the anode P and a given cathode, a gaseous glow discharge will be established between the anode P and the cathode. Assume that anode P in Fig. l is conf nected tota source of positive constant direct 4voltage and" that a voltage sutiiciently negativewith respect ythereto is applied to cathode K-l, so that a glow dischargeexistsV between anode P and cathode K-l. Now, if a more4v Patented` May 6, 1,958.

waaraan; mniaatmwnode K11 is .applicato t G1, the terminal of guide set one, the glow may be established from anode P to the adjacent guide of guide set one and will no longer exist between cathode K-l and anode-P. .Resistancesmayibe inserted-in thek cathode and guide,` circuits so that `,anode current is ,limited `at `any one timeto one cathode, .tonne guideor two guides, -but never `to a lguide and cathode. hns Yit will be lseen that the `glow ,has been translated t clockwise. If next the potential of-.guidevset twoisinade-asmegative as that of guidejset one, the vglow will become .established between anode P and both the G41 and G-2 guides immediately cloekwisenoffcathode Kv-1. '.Ncw, ,if the ,potential of guide Lset .one is made intere ffpositive,` the glow :to .guide one will be extinguished and a glow will exist between anode P and:guide;two only. Hlf`inalty;` ifithe potential of both fguidersets .isffmadeless vnegative, gthe glow will be transferred .'cloclcwisexto @adjacent cathode K-Z. t Thus it may tbe rseenthatxatransfer:from onecathode to an adjacent cathode,or a count of one1has been made.

By arbitrarilynnumbering the `cathodes successively from Izeroto nine ina .givendirectiom the count will progress in an additive mannerifthe `glowtistransferred in that direction. By` samplingrthecathode `potential it is fpossibleltosense electrically `the position ofthe glow discharge. By viewingtthe top or face ofthe tube one may see theA positionfof the glow discharge,V and by placing'numerals onor adjacentthe` tube,-a visual indication of 4thecount may also befprovidedtl Y Milf, lintthe unit` count -described above, the order of lowering (makingmorennegative.) ofthe guidesetpotentials `were reversed, so 'that guide vset two potentials were` lowered ibefor'e guide set one potentials, the discharge would have Jbeen transferred in an opposite, or counterclockwise direction, going from cathode 1 toguide set 2 situated immediately counterclockwise fromcathode` K-l, and =then progressing through the 4remainder -of-a similari butreversed unit count to `be'transferred to cathxItmay be noted thata -uvnit` count (transferrfrom a given "cathodetoan adjacent cathode) is comprised of four distinct states. Since the voltages applied to lower and raisefthe potentials of the guide sets vary thedirection of counting according to their order of application, and `sincezthey are appliedin four dierent stages perun'it count, it maybe `seen that reversing the" count (addition to subtraction, orvice versa) may be/done at any quarter of the counting cycle. t, However, the duration of each quarter-cycle`following reversal Yshould not be much less than-.approximately 60 microseconds vwith presently available tubes, since this is about the minimum time required to complete the transfer of the glow discharge. Thus the fastest counting cycle cannot be completed in much less than about 250 microseconds, and consequently the maximum counting speed which the devicemay be `capable of handling with perfect reliability may be about 4,000 counts persecond. This speed is entirely adequate for numerous applications.

Referring to Fig. .Zth'ere is kshown a diagram illustrating graphically the condition of the potentials on the guides during `each quarter of one complete clockwise counting cycle. The potential with respect toground of guidesetrone isillustrated by line A, vand the potential of ,guide set two is described byline B. It will be seen that the voltages represented by lines A and B are 90 out `of phase, Vwith potential A leading gby one quartercycle. If `the potential -B were-applied to guide-schone, the counting; would `progress `in` a` counter-clockwise manner. It will'be:apparenttothose-skilled in the art'that pairs 1of1fsuchvoltages1rphased-90 apartin accordance ,photocells, whose. outputvoltagesare phased according to direction of motion.

As voltages such as thoseushown graphically in Fig. 2 are applied to the guide sets, the count will progress con tinuously around the tube by repetition of the unit counting cycle. Since the electrodes are spaced symetrically in circular array about the anode, their numeralv designation may be entirely arbitrary. Therefore, no special resetting provisionneedbe made for translating from K-9 to K-I), or from K-0 to K-9, such as would be necessary in prior art counting tubes in which the ele`l ments are arranged in straight-line fashion.

In most counting or translating problems it is neces` .L sary thatfcountsbe'made of many more `than-ten pulses,

and while some additional Acathodes and ,guides may be provided, it becomes desirable to provide succeeding higher order decades so that counts of tens, hundreds, thousands, ten-thousands, etc., may be made. It will be apparent, however, vthat an output :signal `,derived by withudirection are commonly :produced :as outputs from. f

The Root sampling the cathodepotential 4of'one ofthe cathodes `of the tube of Fig. .l is not suitable tor-operating a succeeding similar decadeounter. In ,order that asimilar decadecounter'may'be.operated by the output of the first counter,.two voltages out ofphase according to countingdirection, and ,having.a `rate of repetition one-tenth of `'that the original `-input zvoltages must beA provided. In addition, the-count must-be able to proceed from a higher order decade to `alower order decade, as well as inthe reverse direction.

Referring ftoFig. 3 there Aare shown graphically the guidellset andtcathodelpotentials of the 'tubeGT-ll with respect to groundfo'r ten-counter-clockwise unit counts, or one'counter-clockwise counting cycle.

B represents the potentialon guide set-one of GT1. `As maybe :seen from Figx, thereexists a glow discharge betweenanode? and one' or more guidesduring threefourths of `aunit-eount from -9 vto 0. This is because there is a lowered-potential onteither guide set or both guide -sets during 'three-'fourths of the unit count. But duringl'therst'quarter of'a transfer from K-9 to K-0, or during-fthe last quarter cycle of a ltransfer from K0 to K-9, no discharge exists to either `of the Aguides-of GT-1. This means that during that particular quarter, a succeeding higher order decade attached to be operated upon a count of ten will not have an electrical signal --to indicatethe direction of counting. vHence -a reversal of countingduring Aa-transfer from -9 to 0 -or from 0 to 9 would have `electrical backlash, sothat a GT-Z may-'be causedY to -be three-quarters ofr a unit.

count ,behind orahead of GT`1v by applying guide set voltages ,to GT-Z which lag or lead `GT--1 guide set` voltages by this amount. g

As .shown in Fig. 3, voltage A (which is. connected Vto guide set-,two of tube GT-1) lags voltage B by one quarter count, which is electrically the same as leading voltage B bythree-quart'ers o'f a unit count. age B is applied to .guide set'one of GT-Z, guide set one of GT-Z willhave potentiallagging behind that of guide set onefo'f GT-l by -three quarters of a unit count.` In orderto make "guide set ytwo of GT-2 also lag 4three quarters of a unit count behind guide set two-of GT4, a=voltage showngraphicallyas Ain Figure 3 is applied `to guide-set two=offGT-2. Voltage A -maybeseenito be the inverse of voltage A. In Fig. 3 lines K-(l through Line lA repre-l sentsvthe potential VVon guide set two of GT-l and line Therefore, if volt- 4`5 K9 illustrate, cathode potentials during-ten complete counter-clockwise unit counts, or one counter-clockwise counting cycle. The shaded pulses indicate rises in cathode potentials due to current owvto GT-l cathodes, and the unshaded pulses indicate rises in cathode potentials due to current ow to GT-Z cathodes. It may be noted, and will have been made apparent from the above discussion that cathode current ilows to raise cathode potential in each tube during that quarter of a unit count when none of its adjacent guides are at a lowered potential.

Referring to Fig. 5 there is shown a circuit by means of which pulses of two voltages 90 out-of-phase may be counted and be made to provide suitable voltages for operating a similar but higher order decade without electrical backlash. The two input voltages, which maybe supplied from the Root or Stabler devices, and which may be amplified and shaped, are applied to terminals A and B. The voltage applied to terminal A is used to operate guide set two of GT-l; the voltage applied to terminal B is used to operate guide set one of GT-l and guide set two of GTL-2, and a voltage A from the plate circuit of amplifier V-1 is used to operate guide set one of GT-Z. Because of the phase inversion in amplifier V-1, a conventional direct-coupled amplifier, voltage A' will be the inverse of voltage A. Thus it will be seen that the guide sets of tubes GT-l and GT-Z will be driven by voltages such as those shown graphically in Fig. 3, and hence GT-l and GT-Z will produce output pulses at their cathodes corresponding tothe pulses shown in lines K-0 to K9 in Fig. 3.

All corresponding cathodes -of GT-1 andvGT-Z are connected together and through common cathode re sistors (R.-1 to R-10) to ground potential as shown in Fig. 5. Cathodes K- and cathodes K-4 are connected together as shown -through two diodes D-1 and D4, and the junction point between the diodes is utilized as an output terminal An. Connected as shown the diodes form an or circuit. A positive output voltage will therefore appear at output terminal An whenever K-0 or IK--4 of either gas tube is conducting. Cathodes K-S and cathodes K-1 are similarly connected to an output terminal An through buler diodes D-S and D-S. Similarly,y a Bn channel is formed by connecting cathodes K-Z and K-S to terminal Bn through diodes D-Z and D-7 and a Bn channel is formed by connecting cathodes K-3 and K-7 to terminal Bn through diodes D-3 and D-6. 'Ihe purpose of the butler diodes will be explained below.

As the circuit of Fig. progresses through ten unit counts, or one complete counting cycle, the output voltages on terminals An, An, Bn and Bn will appear in a manner shown graphicallyvin Fig. 4. Voltage An can be seen to have positive steps atthe first quarter `of a zero or ten count when cathode K-0 of GT-l conducts, at the last quarter of a zero or ten count when cathode K-0 of GT-Z conducts, at the rst quarter of a four count when cathode K-4 of GT-l conducts, and at the last quarter of a fourcount when cathode K-4 of GT-Z conducts. Terminals An, Bn and Bn receive similar pulses as shown in Fig. 4.

If the output voltages at terminals An and An are applied to the input circuit of the bi-stable ip-op circuit shown in Fig. 6, output voltages such as those shown graphically in Fig. 4 as An--l and An-1 may be produced by the llip-op.

351 similar to that of Fig. 5. It may be noted, however, thatA l As the positive pulse from cathode K-0 of GT-lappears at terminal An during the first quarter of a zero count, it is applied through resistor R-30 to the grid of the left triode section of duo-triode V-2, driving that section to saturation and decreasing the plate voltage of the The decrease in plate voltage s applied left triode. through resistor R-32 and capacitor C-30 tothe grid of the right-hand triode section of tube V-2, causing that triode to cut off, thereby .increasing its plate voltage.

The saturation current in the left-hand triode causes drop in voltage at terminal Afn-l-l, and the. cutoi of current in the right-hand triode causes an increased volt-` age at terminal An-l-l. These voltages are shown graphically in Fig. 4. As the positive pulse from cathode K-0 of GT-Z appears at terminal An three-quarters of a unitk appears at terminal An during the rst quarter of the live count, and it is applied through resistor R-34 to the grid of the right-hand section of tube V-Z, the flipllop will be caused to change state, so that the rightfhand triode will conduct at saturation and the left-hand triode will be cut olf. This will cause the voltages at terminals- An-l-l and An-l-lA to change as shown graphically in. Fig. 4. While I have shown a specific type of bi-stable device, it will be apparent that transistor ip-ops and other bi-stable devices may be substituted for the circuit of Fig. 6 without departing from the invention.

If the terminals Bn and Bn are similarly connected to an identical ip-ilop, the voltage` Bn-l-l may be obtained at a terminal connected similarly vto terminal An+1. Inspection 'of Fig.` 4 and Fig. 2 will show that the voltages An-I-l and Bn-l-l are substantially outof-phase, and that voltage An-l-l, is the inverse yof voltage Arr-l-l, and further, that the Arr-l-l, A'n-l-l and Bn+1 voltages change state one-tenth as rapidly as Volt-y ages A and B. Hence voltages have been provide'dat terminals An+1, An-l-l and Bn+1 suitable for operat-l ing the guideksets of a succeeding higher order -circuit tube V-l of Fig. 5 will have no counterpart in succeeding decades, since the inverse voltage is supplied. at terminal An-k. Each succeeding decade will consist of the balance of the circuit of Fig. 5, and the A, A', B and B terminals will feed into pairs of ip-ops, each of which may b e similar to the iiip-op shown in Fig. 6. The last, or highest order decade will not, of course, need to have ip-ops following.

Shown in Fig. 8in block diagram form for sake of clarity is a three-decade counter. Input voltages 90 out-of-phase at terminals A and B operate the circuit of'.

Fig. 5 to produce voltages to drive the A and B ilip flops. The output voltages from the Hip-ops drive the second glow tube pair, which in turn, drives a succeeding pair of flip-Hops, etc. In practicing the invention siX and more decades have been cascaded as shown. It will be apparent that other counting circuits may be employed in conjunction with the invention for particular counting applications. For example, counting circuits utilizing hard vacuum tubes may be deemed vto be more suitable in the iirst, or fast lower order decades, and the slower higher order decades may comprise mechanical counting devices. Itv will also be apparent that shaping or amplifyapplied to the succeeding iiip-ops.

-Ifthe count is progressing additively as time prolg'resses, as in the example above, the dip-ilops will'always be triggered by pulses from cathodes of -GT-l, because GT-1 will always be three-quarters of a unit count ahead of GT-Z. If the count is subtracting, the ipops will always be triggered by pulses from GT-2. It will now become apparent that the electrical backlash at a count from 9 to O or from 0 to 9 has been eliminated, since an electrical signal will be present at all timesl to indicate to a succeeding decade the direction of the count. example, if the counter is adding from 9 to 0,` the formerly ambiguous quarter-countbetween 9 and 10 when neither guide of GT- lis conducting will be accompanied For 7 t by a. state of GT-Z which indicates that the count is adding rather than, subtracting.

Shown in Fig. are. means by which an additional visual indication of the count may be obtained. Connected to each common cathode terminal of the glowdischarge tubes is a neon indicating lamp,. each shown as comprising a type NE-2 neon lamp, the. other terminals, of which are returned to a negative potential through resistor R-36. As each cathode conducts, drawing current through its cathode resistor, the voltage is increased, across the neon tube sufficiently to make it ionize andconduct. The neon tube will remain conducting after the cathode voltage has dropped since it is connected through a cathode resistor to ground so as to keep the voltage across, it above the required maintaining potential ofI the neon. tube. However, when the succeeding cathode conducts, the voltage drop through resistor Ita-36 will lower the voltage so as to extinguish the first neon tube as soon as the succeeding neon tube tires. For such operation, the neon tubes utilized must have the property that their minimum signal level plus their minimum maintaining potential be larger than their maximum tiring potential, andV such property is usual in type NE-2 neon tubes. The purpose of the butter diodes (D-1 to D-8) may now be understood. If D-l were not provided, neon tube 0"would fire when cathodes K-4 conducted as well as when cathodes K-0 conducted due to the commonconnection `at terminal An. Hence it may be seen that each` diode serves tol prevent a false indication on an` associated neon tube when the associated cathode is not conducting. It will be` apparent that the diodes may beeliminated if the externaly neon visual indication is` not required on a particular decade.

It will`be apparent that the guide set potentials applied to the GT-l and GT-Z pairs in each decade mustl be three-quarters of a unit count out-ot-phase, and hence it becomes important to provide a means by which this may be assured initially. It is` also desirable in most counting devices to have a re-setting means to return the count to zero or to some other desired count.

Shown in Fig; 7 is a switching circuit which may be utilized in re-setting the invention. The system shown resets the counter to the second quarter (2/4) of the zero-count. Reference toV Fig. 3 will show that during any 2/4 period both guidesets ofGT-l will be conducting, that guide set 2 ot GT-2 will be conducting, and that guide set 1 of' GT-2 will not be conducting. In order to cause such conduction, all K-3 and K-9 cathode resistors (R-4and` R-10) are connected to a positive potential by contact arm a of `manual reset switchS-IL Next, contact arms b and c reset Vswitch Sel disconnect all flip-flop common-cathode resistors, making the voltage high on all guide electrodes and thus forcing the glow to transfer to a` cathode. Then, contact arm d of switch S-l lowers the anode supply voltage to the glow transfer tubes, so that no glow will then exist to any` cathode and then contact arm e of switch: S-1 connects the zero` cathode resistor to a high negative potential so that conduction is'caused between the anode and cathode K-0. In order` to effect the foregoing steps, manual reset switch S1 of Fig. 7' is operated so as to move its contact arms clockwise as shown in Fig. 7. Ifv switchI S-l is then moved counterrclockwisqthe anode supply voltageis againY raised and the K-0 cathode resistor Rwl is again grounded, It will beapparent that a. switching circuit similar to that of Fig, 7 may be pro.- vided for each decade, and` theresetting `may be done either by individual re-setting or by ganging the` several switchesto reset all decades simultaneously. The contact arm c re-connects` all cathode resistors of the Byflipflops to their supply voltage, transferring theA glow from cathode K- to guide one of GT-l and guide two of' flop` assume a state so as tocause the voltages on theM Vtractive nature.

aforementioned guides to be low. Next, contact arm B connects the cathode resistors of all A flip-hops totheir supply voltage. The voltage applied to the` K-3 and K-9j cathode resistors of a stage causes the succeeding A y tiip-tlops to assume a state so that A voltage is low and A' voltage is high. This causes no change in GT-l, b ut causes the glow discharge in GT-2` to exist on the two guide electrodes located between the K-O. and K-9 cathode of GT'-2. `As reset4 switch S-1 reaches its counter-clockwise limit, contact arm a re-connects the K-3 and K9 cathode resistors toground. The voltages at terminalsl Aand Bare low, and' the voltages at terminalsv A" and B" are high. It may be seen in Fig. 3 that` the existing conditions are those which prevail upon a count of 1/2 (between 0 and l). The counter is' then ready to receive4 input' pulses of either additive or sub- Itwill' be apparent that while we have shown a reset systenr connected so asl to return the count to oneehal that/the principles illustrated may be .utilized t`o return the count to any desired number.

While there is shownA illustratively a decade counter, it may be seen that the invention is not limited to counters utilizing a base 4number of ten.` Glow discharge tubes similarV to the type shown, but having a greater or lesser number of' cathodes and guides may be utilized in count ing lwith base numbers greater or smaller' than ten. Assume that the glow transfer tube provided has eight cathodes and sixteen guides in order thatl the counter may utilize a base-number of eight Fig. 9 shows the glow tube cathode output pulses and hip-flop output pulses` so as to count reversibly and to provide the correct output voltages for a succeedingl higher order decade. In order toprovide the correct voltage at terminals An, A'n, Bn and- Bn, ther corresponding cathodes of the two eightposition glow tubes wouldA be connected together; and the pairs of cathodes would beI connected to the terminals as follows-z The zero andi three cathodes would be connectedfto the An terminal', andl the four and"seven cathodes would he connected to the An terminal; the

one 'andi six cathodes would be connected to the Bn terminal;l and` the two andL tive cathodes would be connectedL togthe B' zterminal.

While the ten counter and the eight counter have been illustratedi respectively/in Figures 4 and 9a as providing symmetrical andA displaced output voltages, it is not necessary that such output voltages be provided; rLhe voltages applied' to the succeeding hip-flops need not-be symmetricalf nor mustf'they be 90` out-of-phase. lt is necessary only that the output voltages each have two-distinct; states during each higher order counting cycle, and that the A output voltages doA not change state. at` the same time as the B output voltages. Counters constructed according to the invention which utilize anV odd baseynumber may utilize asymmetrical output' voltages tov drive succeeding flip-ops. Such a system sillustrated` graphically in' Fig. 9b for counting withl a basenumber of ""sevem Itwill become apparent frominspection of- Fig. 9b that the Zero andv three cathodepairs are connected toy the Alz terminal;` the four andf six cathodeV pairs to the An terminal; the two and five cathode pairs `to'the Bn terminal', and the one and six` cathode pairsv to the; Bflz terminal. It' maybe seen/'that the outputvoltages are asymmetrical and' not displaced: 90 degrees. ln' practice it is desirable that the output voltages be made as` symmetrical as possible in order to maximize, the reliability of the counter if noise is present. If an output voltage to the succeeding ip-iiops isV greatly unsymmetrical, so that one state is very short in duration, and the other state is very long. theamount of noise that the counter will rejectwithout counting error will' be limited by the duration ofthe shortened output pulse,v since a succeeding flip-flop may not be triggered if' the pulse time is too short.

Various other suitable connections from the corre= 'It will also be apparent that the invention may be con-` nected to actuate numerous devices upon occurrence of any predetermined count as well providing visual indications. For example, relays connected to each decade to be actuated by rises in voltage of particular cathodes may have their actuated contacts connected in series, so

that closure of all the relays simultaneously actuates anyr Numerous actuating circuits desired electrical device. will be apparent to those skilled in the art.

While there have been shown in the drawings circuits labelled with specific values of resistance, capacitance, supply voltages and specific tube types, it is to be understood that such values and types are exemplary only, and

that numerous possible changes will be readily apparent to those skilled in the art upon perusal of the disclosure without departing from the invention. It is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and speciiic features of the invention herein described, vand all statements of the scope of the invention which, as a matter of language, might besaid to fall therebetween.

Having described our invention, what w'e clainil as new and desire to secure by Letters Patent is:

1. A reversible direct-coupled counting circuit ycomprising in combination a pair of multi-'electrode gaseous discharge counting devices each having 'a plurality of numbered elements, each numbered element being operable to produce an output pulseupon occurrence of a count corresponding to its number, and'each device having a pair of translating means responsive to a pair of applied voltages phased in accordance with counting direction for translating a current to successive numbered elements of said devices, a pair of bistable ilip-ops connected to receive pulses from two groups 'of said`elements to change state twice during each unit count of an adjacenthigher order counting circuit, and 'circuit means connected Ato each of said iiip-flops to apply Voltagesrto operate similar pairs of translating means of said succeeding higher order counting circuit. l

2, A reversible counting circuit having a pairof countingy devices, yeach of said counting devices having a plurality of numbered elements,r each vnumbered element being operable to producea signal upon occurrence of a count corresponding to its number and each device having a pair of translating means responsive to a pair of applied voltages phased in accordance with counting direction for translating a current tosuccessive numbered elements of said devices, and a pair of bistable iiip-ops connected to receive alternately pulses from selected groups of said elements to change the state of each iiipop twice during each unit count of an adjacent higher order counting circuit. V

3. A reversible countingcircuit having a pair of multielectrode counting devices, each of said counting devices having ananode element and a plurality of numbered elements .arranged in circular array about vrsaid anode element in a gas-iilled envelope, voltage means connected to said anode element-and said numberedelements to causea gaseous discharge current between said anode and one of said numbered elements, pairs of translating elements individual to leach device ,each responsive to a pair of applied voltages phased in accordancewith counting -direction for translating said gaseous discharge rent to. successive numbered elements', the correspondingly numbered elements of each device being connected to common terminals, and a pair of bistable hip-flops'. each having a pair of input circuits, each of said input circuits being connected to a pair of said common terminals to change the lstate of each of said flip-ops twice during each unit count of an adjacent higher order counting circuit. v

4. A reversible counting circuit having a pair of counting devices, each of said counting devices having a plurality of numbered elements, each numbered element being operable to produce a signal voltage upon'occurrence ot a count corresponding to its number and each device havinga pair of translating means responsive to applied voltages phased in accordance with counting direction for translating a current to vsuccessive numbered' elements vof said devices, the applied voltages to said translating means being de-phased a fraction of a unit` count,` and a pair of bistable iiip-ops connected to receive alternately pulses from selected groups of said numbered elements to change the state of each flip-flop twice duringeachunit count of an adjacent higher order counting circuit connected to be operated by output voltages from said Hip-flops.

5. A reversible-direct-coupled counting circuit having a pair'of multi-electrode counting devices, each of said counting devices having a plurality of numbered elements, each numbered element being operable to produce a voltage signal upon receipt of a translatable current, pairs of translating elements individual to each device each responsive to applied voltages phased in accordance with counting direction for translating said current successively circuit having similar translating elements connected ,to be actuated by the output voltages ofsaid flip-flops.

6. Reversible counting apparatus comprising a plurality of translating circuits of accending order, each of., said translating circuits having a pair of counting devices. having a plurality of numberedelements, each nurnbered element being operable to produce a signal voltage upon occurrence of a'count corresponding to its num-V ber and each device having a pair of translating means responsive'to applied voltages phased in accordance with counting direction for translating a current to successive numbered elementsof said devices, and a pair of bistable ilip-ops connected to receive said signal voltages from selected groups of said numbered elements to change state twice during each unit count of the succeeding higher order translating circuit.

7. A reversible counting circuit having a pair ot counting devices, each of said counting devices having a plurality of numbered elements each numbered element beling operable to produce a signal upon occurrence of a count corresponding to its number and each device having a pair of translating meansl responsive to a pair of applied voltages phased in accordance with counting direction for translating a current to successive numberedV elements of said devices, anda plurality of numbered indicating means connected to said numbered elementsL to indicate the number of the count, the correspondinglyy numbered elements of said devices being interconnected.

8, A reversible counting circuit comprisingin com-1 bination a pair of multi-electrode gaseous discharge counting devices each having a plurality of numbered elements, each numbered element being operable to produce an output voltage upon occurrence of a countcor'- -responding to its number, and each device having trans.-

lating elements responsive to applied voltages phased in accordance with counting direction for translating a .cur-

rent to successive numbered elements of said 'devicesQthe correspondingly numbered elements of each device being connected together andthe voltages applied to the transt masacre 11 lating` elements of one .dexffice` being dephased with respect to the voltages applied tov the translating elements offthe other device, and actuating means connected to groups of said numbered elements to be operated upon occurrence of a predetermined count.

9. A reversible counting circuit having atpair of multielectrode counting devices, each of said counting'devices havingan anode element and a plurality of numbered elements arranged successively in circular array about said anode element, voltage means connected to said anode element, and said numbered elements to cause a current ow between said anode and one of said numbered elements, `pairs of translating elements individual to Aeach device, each pair of elements being responsive to applied voltages phased in accordance with counting direction for translating said current -ilow to successive numbered elements 'in each counting device, the` correspondingly numbered elements of each device being connected` to common terminals, the voltages applied lto the pair .of

translating elements of one counting device being de-y phased atfraction of a unit count with` respect to the voltages applied to the pair of translating elements -of the other counting device, and a pair of bi-stable'iliip-op devices each having a pair of input terminals, cach of said input terminals being connected to two of'saidcom-` mon terminals to change the state of eachofsaiddlipop devices twice during each unit count ofl an adjacent higher order counting circuit.

l0.` A reversible counting circuit having apairoimultielectrode counting devices, each` of saidcounting devices having an anode element andv ten numbered cathode Velements arranged successively-in circular array about said anode element, voltage means connectedto saidanode element and to said cathode elements to cause a current flow between said anode element and one. ofv said cathode elements, guidemeans interposed between; successive cathode elementsV and responsive to applied voltages phased in accordance `with counting direction for-transferring said currentllow to successive cathode elements, the voltages to the guide means of each counting device being three-quarters of a unit count out of phase, the correspondingly numbered cathodes of each device. being connected to common terminals, and a pair of bi-stable.

flip-flop devices each having a pair of input circuits, each flip-flop input circuit being connected to pairs of common terminals to receive actuating voltagesignals .atthe end of and the beginning of different ,instantsofa unit count of higher order `to produce two phase-displaced voltages to be applied tosimilar guide means of a. succeedingthigher order counting circuit. t

ll. A reversible counting circuit having a pair of` counting devices, each of said devices having a plurality of numbered elements, each numbered element. being operable to produce a signal upon occurrence of a count corresponding to its number and each device having a pair of translating means `responsive: to a pair of applied voltages phased in accordance 'with counting direction 'for translating a current to `successive,numbered elements of said devices, and a pair of bistable iiipt-liops connected to groups of numbered elements to receive alternately pulses at the end and beginning of different half-cycles of two phase-displaced voltages applied to a succeeding higher order counting circuit.

l2. A reversible counting circuit having apair of counting devices, each of said' devices having a pluralityof` andpulses on its other input circuit during second and fifth instants of time, the second of said flip-flops being connected to receive pulses on one of its input circuits during third and eighth instants of time and pulses onits other input circuit during fourth and seventh instants of time. v

13. A reversible counting circuit having a pair of counting devices, each of said devices having a plurality of numbered` elements operable to produce an output signal pulse upon receipt of a translatable current flow anda pair of translating means responsive to a pair of applied voltages phased in accordance with counting direction for translating said current tlow successively to said numbered elements, correspondingly numbered elements-of f each device being interconnected, and said pairs of applied voltages being de-phased a fraction of a unitcounting cycle, and a pair of'bistable flip-ops each having a pair of input circuits, the first of said Hip-flops being connected to receive pulsesv on one of its input circuits during first and sixth instants andv on its other-input circuit during second and fifth instants, the second of said tlip-,ops being connected to receive pulses on one of its input circuits during third and eighth instants and on its other input circuit du'ring fourth and seventh instants, and circuit means connected to -apply the output'voltages of said flip-flops to the translating means of a succeeding higher order reversible counting circuit.

14. A reversible counting circuit having a pair of counting devices, each of said devices having a plurality of numbered elements operable to produce an output signal pulse upon receipt of a translatable current llow and a pair of translating means responsive 'to a pair of applied voltages phased in accordance with counting direction for translating said currentow successively to said numbered elements, the correspondingly numbered elements of each device being interconnected, and said pairs of applied voltages being de-phased a fraction of a unit counting cycle, and a pairtof'bistable flip-flops each having a pairof input circuits, the first of said flip-hops being connected to receive pulses at one of its input circuits during first and fourth instants and lat its other input circuit during fifthtand-eighthinstants, the second of said flip-flops being connected to receive pulses at one of its input circuits. during second and seventhinstants and 'at its other input Vcircuit during third and sixth instants.

15. A reversible counting circuit comprising in combination a pair of multi-electrode counting devices, each of said counting devices having an anode element and a base number of numbered elements arranged successively in circular array about said anode element, means for applyinga potential between said anode element and said cathode elements to cause a current ow between said` anode element and one of said cathode elements, guide elements interposed between successive cathode elements,

each lof? said guide elements being operable upon receipt of an operating potential to attract said current ilow away from its adjacent cathode element, each of said guiderelements situated vclockwise from its respective adjacentcathode'being connected toa first input terminalof each device and each of said guide elements situated counterclockwise from its respective `adjacent cathode being connectedv to a secondinput terminal of each device, nmeans for applying a pair of alternating Yinput potentials individually to the 'first and second linput terminals of each device, the potentials applied to the input terminals of one of said devices being de-phased with respect to the potentials applied to the input terminals of the other of said devices, circuit means interconnecting the correspondingly numbered cathode elements of each device to provide common terminals, a pair of bi-stable devices e'ach having a pair of input circuits and output circuits, and circuit means connecting a different pair of said common terminals to eachinput eircuitof said bi-stable devices.

16. reversible counting circuit having a pair of count- A 2,833,476 4 13 14 ing devices, each of said counting devices having a base four of said common terminals being connected to difnumber of numbered elements, each numbered element ferent control terminals of a pair of bi-stable devices. being operable to produce a potential upon receipt of a References Cited in the me of this patent translatable current, and each device having a pair of translating means responsive to a pair of applied input 5 UNITED STATES PATENTB voltages phased in accordance with counting direction for 21774534 Dunn Dec' 18 1956 translating said current successively to said numbered y OTHER REFERENCES elements, the correspondingly numbered elements 0f the A Cold Cathode Batching Counter by Tooke, Elecdevices being interconnected at common terminals, and 10 tronic Engineering, page 160, April 1954. 

